Entometa fervens (Walker, 1855)
Common Gum Snout Moth
(formerly known as Opsirhina fervens)
Don Herbison-Evans
Stella Crossley & John Stumm

Entometa fervens
smooth form
(Photo: courtesy of Edward Tsyrlin, Melbourne, Victoria)

This is a large fleshy Caterpillar with soft downy hairs. It is sometimes smooth, sometimes rough, sometimes brown, and sometimes grey. The variable nature of the caterpillars suggests that the name Entometa fervens is being applied to a complex of several species. More investigation is needed to clarify this.

Entometa fervens
rough form
(Photo: courtesy of Trevor Jinks, North Burnett, Queensland)

The caterpillar has a prominent projection on the back near the posterior end, and a pair of fleshy filaments behind the head. It is solitary, and feeds at night on a variety of plants in MYRTACEAE such as:

  • Gum Trees ( Eucalyptus species ), and
  • Lilly Pilly ( Syzygium smithii ).

    Entometa fervens
    hairy form, female
    (Photo: courtesy of Julie Earl, Collie, Western Australia.)

    By day, it rests well camouflaged, flattened against the stem of its foodplant, with the hairs along the sides disguising its legs. Also: the rounded knob on the tail mimics a broken-off gum tree twig.

    Entometa fervens
    display posture
    (Photo: courtesy of Martin Purvis)

    If disturbed, the caterpillar rears up its tail and its thorax, tucks its head under the body, displays two pale-blue edged black bands that are normally hidden between segments, and stiffens the two horns behind the head.

    Entometa fervens
    display posture
    (Photo: courtesy of Joel Hughson, Perth, Western Australia)

    The caterpillar grows to a length of about 7 cms.

    Entometa fervens
    (Photo: courtesy of Craig Nieminski, Darwin, Northern Territory)

    It pupates in a white papery cocoon between two leaves on the foodplant.

    Entometa fervens
    (Photo: courtesy of the Photography Group, Centre for Biodiversity Genomics, University of Guelph)

    The moths are rusty coloured with variable patterns of dotted and zigzag lines, and with stout hairy bodies. The wings of the females vary in colour from orange through brown to cream, The hindwings of the male vary from orange to through brown to black, The moths often have a dark patch under the hindwing, and black antennae which can be used to distinguish them from Entometa guttularis. The adult males have a wingspan up to 5 cms. The females have a wingspan up to 8 cms.

    Entometa fervens
    (Photo: courtesy of CSIRO/BIO Photography Group, Centre for Biodiversity Genomics, University of Guelph)

    The species is found mainly in the southern half of Australia, but has been found in:

  • Northern Territory,
  • Queensland,
  • New South Wales,
  • Victoria,
  • Tasmania,
  • South Australia, and
  • Western Australia.

    Entometa fervens
    Female with eggs

    The female lays her eggs in untidy clusters on leaves of a food plant. The eggs are mottled brown and ovoid, with a length of about 2 mm. Many are laid lying on their sides. An adult female captured in Brisbane at night in May 2003 had laid 20 -25 eggs by morning. The eggs hatched 11 days later and the caterpillars were reared on the young shoots of a Red River gum.

    Entometa fervens
    eggs magnified

    Most pupated between after 7 to 8 weeks. The last larva delayed pupation until 11 weeks after hatching. After a pupal stage of 6 - 7 weeks, one female and two male adults emerged. The specimen that delayed its pupation by an extra 3 weeks actually emerged as a female adult moth 3 weeks later, so emerging at nearly the same time as those that had pupated early.

    We have observed that females bred in captivity lay eggs the next day after they emerge from the pupa, and that these eggs are usually unfertilised. These moths are similar to domestic poultry in this regard.

    Entometa fervens
    Female underside
    (Photo: courtesy of Graeme Cocks, Townsville, Queensland)

    Further reading :

    David Carter,
    Butterflies and Moths,
    Collins Eyewitness Handbooks, Sydney 1992, p. 208.

    Ian F.B. Common,
    Moths of Australia,
    Melbourne University Press, 1990, pls. 12.21, 12.22, p. 390.

    Pat and Mike Coupar,
    Flying Colours,
    New South Wales University Press, Sydney 1992.

    Peter B. McQuillan, Jan A. Forrest, David Keane, & Roger Grund,
    Caterpillars, moths, and their plants of Southern Australia,
    Butterfly Conservation South Australia Inc., Adelaide (2019), pp. 92-93.

    Peter Marriott,
    Moths of Victoria - Part 1,
    Silk Moths and Allies - BOMBYCOIDEA
    Entomological Society of Victoria, 2008, pp. 10-11.

    Buck Richardson,
    Tropical Queensland Wildlife from Dusk to Dawn Science and Art,
    LeapFrogOz, Kuranda, 2015, p. 101.

    Francis Walker,
    Catalogue of Lepidoptera Heterocera,
    List of the Specimens of Lepidopterous Insects in the Collection of the British Museum,
    Part 6 (1855), p. 1419.

    Paul Zborowski and Ted Edwards,
    A Guide to Australian Moths,
    CSIRO Publishing, 2007, p. 153.

    Australian Butterflies
    Australian Moths

    (updated 27 September 2012, 11 March 2023)